Rolling mill, roll stand, as well as method for replacing roll stands in a rolling mill

ABSTRACT

In order to allow simple replacement of the roll stands in the case of a rolling mill for rolling elongated material, having multiple roll stands disposed in a line, forming a central caliber opening, wherein the roll stands are disposed in a stand position, in each instance, and can be displaced into at least one change position, in each instance, each stand position has an intake coupling, and the intake coupling has a coupling part on the roll stand side, as well as a coupling part on the drive side, wherein the drive-side coupling part is provided in axially fixed manner on the stand position.

The invention relates to a rolling mill for rolling elongated material, having multiple roll stands disposed in a line, forming a central caliber opening, whereby the roll stands are disposed in a stand position, in each instance, and can be displaced into at least one change position, in each instance, and, in particular, to a rolling mill in a compact construction, for rolling elongated material, having multiple motor-driven roll stands disposed in a line, forming a central caliber opening, in a C-stand that can be alternately equipped. Likewise, the invention relates to a roll stand having at least two driven rolls (2, 3) and having at least two intakes, as well as a roll stand having rolls for absorbing rolling forces that occur when rolling elongated material, as well as to a method for replacing roll stands (12) in a rolling mill.

The invention is particularly to be used for stretch-reducing rolling mills (SRW-BCO), dimensional rolling mills (MW-BCO), and extracting rolling mills (AZW-BCO).

Rolling mills for rolling elongated material are known not only with two-roll stands but also with three-roll stands or four-roll stands, whereby it is also known to incline the rolls to change the caliber diameter. In two-roll stands, the offset is 90°, in three-roll stands it is 60°, and in four-roll stands it is 45°.

The invention is based on the task of making available a rolling mill of the type stated, a roll stand of the type stated, as well as a method of the type stated, for replacing roll stands in a rolling mill, which allow the most operationally reliable possible replacement of the roll stands, with the most compact possible design.

In order to accomplish this task, a rolling mill for rolling elongated material is proposed, having multiple roll stands disposed in a line and forming a central caliber opening, whereby the roll stands are disposed in a stand position, in each instance, and can be displaced to at least one change position, in each instance, and whereby the rolling mill is characterized in that each stand position has an intake coupling, and the intake coupling has a coupling part on the roll stand side, as well as a coupling part on the drive side, and the drive-side coupling part is provided in axially fixed manner on the stand position. Thus, a particularly simple coupling possibility is advantageously obtained for the rolling mill, which possibility can furthermore be used in operationally very reliable manner, because the degrees of freedom of the two coupling parts of the intake coupling are restricted by means of the fixed provision of the drive-side coupling part on the stand position, and successful coupling-in is influenced only by the position of the coupling part on the roll stand side. If the roll stand is guided linear to the stand position, without play, a degree of freedom occurs only for coupling the intake coupling, as is immediately evident. Consequently, precise and operationally reliable coupling-in by way of an intake or the corresponding intake coupling to a drive motor is ensured by means of the proposed configuration.

A rolling mill having an intake coupling can also advantageously be configured by means of two intake couplings per roll stand and per stand position, whereby the two intake couplings are in effect axial to their axes of rotation, in each instance, and the axes of rotation are oriented parallel, and whereby the two intake couplings are disposed on one side of the line. In this regard, a roll stand or a rolling mill according to this configuration can be set up or put into operation in just as simple and operationally reliable a manner as when only a single intake coupling is provided, because the intake couplings, which are oriented relative to one another, can be handled like a single coupling. In this connection, the two intake couplings, which can have a common drive or also two individual drives, can be coupled in a single assembly step, whereby in particular, only the roll stand needs to be moved. By means of the two intake couplings, the forces or moments that must be transferred from the drive to the roll stand by way of a single coupling are reduced accordingly. As a result, the coupling diameters, in particular, are reduced, thereby allowing the roll stands to be built narrower, accordingly.

However, it is not absolutely necessary, in order to ensure operationally reliable coupling, for the roll stand to be moved for the coupling process. An embodiment in which the drive-side coupling part is structured to be axially movable is also possible.

In the case of an advantageous embodiment of the rolling mill, a drive having a drive motor can furthermore be provided on at least one stand position, which motor is connected with a distributor gear mechanism, which has at least two power take-offs, whereby the power take-offs, in each instance, have a drive-side coupling part of an intake coupling. Cumulatively to this, the drive-side coupling parts can be oriented parallel and in the same direction on the rolling mill. By means of these configurations, a rolling mill having a roll stand is made available, which advantageously has one, two, or more intake couplings. In this connection, the possibility exists, on the one hand, of transferring more torque to the roll stand, by means of the numerous intake couplings, or, on the other hand, of driving different modules of the roll stand separately from one another. In the case of suitable configurations of the roll stands, these can also be provided merely with fewer coupling parts on the power take-off side, if only lower torques are required, whereby structural free spaces are left in the regions in which other drive-side coupling parts are found, so that these coupling parts can run along freely.

A parallel and same-direction orientation of these drive-side coupling parts furthermore advantageously brings with it a great degree of flexibility in the selection of the drives. Thus, a single or also multiple drives can optionally be coupled with the roll stand, whereby in particular, only the roll stand needs to be moved for coupling-in, but this does not necessarily have to be provided in this manner.

The terms “parallel” and “in the same direction” relate, in this connection, to the different axes of rotation of the coupling parts, in each instance, whereby “in the same direction” means the same direction of rotation. A “distributor gear mechanism” refers to any gear mechanism that has more power take-offs than drives, independent of whether a branching of power—by means of different speeds of rotation at the power take-offs—takes place. In this regard, a distributor gear mechanism can also be a helical gear mechanism.

Preferably, as is known from JP 57-121810 A, for example, the roll stands, in each instance, are disposed in a stand position, in each instance, and can be moved to at least one change position, in each instance, and whereby precisely one change position is provided per stand position, and a change position of a first stand position is provided on one side of the line, and a change position of a second stand position is provided on the other side of the line. The change positions with reference to the stand positions allow a particularly compact rolling mill, in which a change in roll stands can be undertaken in particularly operationally reliable and fast manner, accordingly. In the rolling direction, in particular, in other words in the axial direction of a roll stand disposed at a stand position, the construction length of the rolling mill is reduced, because space for additional modules does not have to be kept available on both sides of the roll stands. Free spaces are obtained particularly in the change positions that are present on both sides of the line, in the axial direction relative to the change positions, which spaces can additionally be utilized for assembly, thereby making it possible to increase the operational reliability, particularly during a stand change, in advantageous manner, if this space is not being used for other units. Another advantage of this arrangement occurs in the placement of drive motors for the rolling mill, which now can also be disposed on both sides of the line, if necessary, and can be designed approximately up to twice the diameter of the drive motors that could originally be used, because of the free space that is now available.

In this manner, it is particularly possible, with a suitable configuration, to create a high-power rolling mill in a compact construction, for rolling elongated material, having multiple motor-driven roll stands disposed in a line, forming a central caliber opening, and a method for simple replacement of the roll stands, on the most confined possible space. The most varied roll stand types can be used in this rolling mill, if the configuration is suitable. The intake couplings of the roll stands can couple automatically when they are pushed into the rolling mill stand, as will be explained in greater detail below. The drives can be accommodated in space-saving manner, as has already been indicated above. If the configuration is suitable, the space requirement for moving the change carriages can be kept low.

In order to make available a particularly compact and space-saving rolling mill, the stand positions along the line can be numbered continuously for a rolling mill, whereby all the odd-numbered change position are provided on one side of the line, and all the even-numbered change position are provided on the other side of the line. It is immediately evident that in the case of this configuration, the stand positions can be disposed in particularly space-saving manner, in the rolling direction, by means of the alternating arrangement of the change positions, and thus uniform construction space is made available on both sides of the change positions, for assembly and set-up work.

In another advantageous embodiment, in a rolling mill, the change positions of the roll stands, in each instance, can be provided on a change carriage, whereby the change carriage has at least one further change position. This further change position serves for keeping available a roll stand to be put in place. A roll stand to be removed from the rolling mill after rolling can thus be guided to a first change position, and afterward, the roll stand kept available at the further change position can be guided back to the stand position immediately, as soon as the change carriage has been moved accordingly. Thus, as is directly evident, the set-up times at the rolling mill are reduced to a minimum. The rolling mill can be put back into operation immediately after the change in the roll stands, whereby the removed roll stand can be guided to its further use, for example a maintenance procedure, after the rolling mill has been put into operation.

Furthermore, a rolling mill having a change carriage that has two change positions can advantageously be configured in such a manner that the change carriage has at least four change positions, one change position and one further change position, in each instance, for two stand positions, in each instance, whereby the two change positions are spaced apart from one another in accordance with the distance between the two stand positions, and the two further change positions are spaced apart from one another in accordance with the distance between the two stand positions. It is evident that in this way, replacement of two roll stands can advantageously take place simultaneously at the two stand positions. It is furthermore also possible that the change carriages can have change positions and further change positions for all the stand positions present in a rolling mill that can be equipped from one side of the line, at the same time.

For a rolling mill having a change carriage that has at least four change positions, it is furthermore advantageous if the change positions and the further change positions are spaced apart from one another, relative to one another, in each instance, at least by the width of a roll stand, preferably by the distance between the stand positions. By means of this configuration, it is possible to reduce the displacement path of the change carriage to a minimum, if the center of the stand position or the center of a roll stand, in each instance, is defined as the starting point for the distance or width measurement. In this connection, here “center” means the axially central position along the rolling direction.

It is understood that a change carriage having two or more change positions is advantageous, even independent of the other characteristics, for a rolling mill for rolling elongated material, having multiple roll stands disposed in a line, forming a central caliber opening, whereby the roll stands are disposed in a stand position, in each instance, and can be moved to at least one change position, in each instance. This is independent of whether the two change positions are used only for one stand position or for two stand positions. If these are used only for one stand position, a fast and operationally reliable stand change takes place in the most confined space, in that a roll stand that is kept available on the change carriage, at the first change position, can quickly be positioned in such a manner, by means of moving the change carriage, that it is brought to the intended stand position and operation can quickly be resumed again, after the change stand to be replaced has been brought to the second change position. If these are used for two stand positions, then two roll stands to be replaced can move from their rolling position to their change position, at the same time, and be transported away by the change carriage, while at the same time, two roll stands move to their change position and from there are brought to their rolling position, by way of another change carriage. Other set-up work, for example removal transport by crane, can then take place from the change carriage, while the rolling mill goes back or is back in operation. In this connection, it is understood that the advantages can be cumulated, if applicable, by means of multiple change positions on one change carriage, in each instance.

Preferably, as is known from JP 57-121810 A, for example, at least one roll stand is disposed on a change shoe, and the change shoe can be moved on a change track that is inclined from the horizontal. The use of a change shoe in connection with a change track offers the advantage of positioning the roll stand within the rolling mill in simple and operationally reliable manner, particularly at the stand position of the rolling mill, even if the rolls of the individual roll stands are inclined relative to one another in their rolling position. The angle of inclination can be predetermined by the inclination of the change track, which can also be adjustable, if necessary, so that the roll stands themselves can be structured in simple manner, and preferably can even be structured to be identical to one another or very similar. In this connection, it can be provided that positioning of the roll stand with the change shoe advantageously takes place at a right angle to the rolling direction of the rolling mill. In this way, the roll stand, which contains rolls as the rolling tools, is oriented relative to the rolled material, and requires no or extremely slight adjustment work, in the case of play-free displacement of the change shoe on the change track.

The inclination of the change track relative to the horizontal already brings about operationally reliable positioning of the roll stand that can be moved on the change track, which stand is accelerated downward along the change track, in the stand position, by means of its own gravity, and, in this manner, can easily be positioned, in operationally reliable manner, on a stop, a contact surface, a brake block or brake wedge, or something similar. Further securing to prevent unintentional displacement of the roll stand can be, but does not have to be guaranteed by means of additional securing means.

In this connection, a rolling mill, in an advantageous embodiment, can have a change track that has a region inclined relative to the horizontal, as well as an essentially horizontal region. In the horizontal region, set-up work, in particular, can be undertaken in simple and operationally reliable manner. Furthermore, the use of energy for horizontal displacements is minimal, so that in this region, displacement can take place with correspondingly little energy expenditure.

Preferably, the essentially horizontal region of the change track is provided on a change carriage. This particularly allows a simple structure of the change carriage, whereby a roll stand provided on the change carriage can easily be held in position by means of corresponding locking devices, such as, for example, wedges, brake blocks, stops, or the like.

Corresponding to the advantages explained above, with regard to locking a roll stand in place, it is particularly advantageous if the region of the change track that is inclined relative to the horizontal is provided in the stand position and inclines down into the stand position. In this manner, corresponding positioning into the rolling position takes place in the stand position, and can be implemented by means of a fixed stop or the like, at the end of the change track, which ends in the stand position, with a simple construction.

It is understood that the characteristics relating to a roll stand with a change shoe are advantageous for a rolling mill even independent of the other characteristics of the present invention.

An advantageous embodiment of the rolling mill furthermore results if at least one roll stand has an intake and the intake can be coupled with a drive motor by way of an axial intake coupling, whereby the intake coupling has a coupling part on the roll stand side and a coupling part on the drive side, and whereby the axis of rotation of the intake coupling is oriented parallel to the change track. This embodiment of the rolling mill, particularly the configuration of the coupling parallel to the change track, allows a particularly simple and, above all, automatic coupling possibility of the roll stand or of the intake with the drive motor or a gear mechanism of the drive motor, and is correspondingly advantageous independent of the other characteristics of the present invention in the case of a rolling mill for rolling elongated material, having multiple roll stands disposed in a line, forming a central caliber opening, whereby the roll stands, in each instance, are disposed in a stand position and can be moved along a change track, in each instance, to at least one change position, in order to guarantee fast and operationally reliable roll replacement.

By means of the orientation of the axis of rotation as explained above, automatic closing of the coupling is guaranteed, because the two coupling parts are positioned precisely, relative to one another, along the displacement direction of the roll stand, and further, particularly manual coupling activities can be eliminated. It is immediately evident that the set-up time of the rolling mill can be reduced to a minimum by means of this embodiment.

In addition to the above characteristics, a rolling mill can advantageously have at least one roll stand extraction apparatus having a hydraulic extraction cylinder. As is immediately evident, such an extraction unit is advantageous for fast and operationally reliable set-up of a rolling mill, because manual set-up, for example by manually hooking chains and the like in place, can be eliminated.

Alternatively or cumulatively to the above characteristics, accordingly, a roll stand having at least two driven rolls and having at least two intakes is also proposed, which is characterized in that each intake has a coupling part on the roll stand side, and the coupling parts on the roll stand side are oriented parallel and in the same direction. It is advantageous that in this way, the roll stand can be coupled from one side, with a drive or also with multiple drives, in structurally simple, space-saving and operationally reliable manner, whereby in particular, only the roll stand needs to be moved. However, a movement of the roll stand for coupling does not necessarily have to be provided. Alternatively, a drive for coupling the coupling parts, in each instance, can be provided on a roll stand, for example, or also on a stand position, axial to the roll stand, but this requires further units and thus brings about susceptibility to errors and an increased construction space.

Alternatively or cumulatively to the above characteristics, a roll stand having at least four driven rolls is proposed, to accomplish the task stated initially, which roll stand is characterized in that two rolls, in each instance, are mounted on a common stand part, whereby the two stand parts in turn are mounted on a stand body. In this case, the task stated initially is accomplished in that great stand moments and rolling forces can be absorbed and distributed in particularly advantageous and operationally reliable manner, by means of the roll stand.

An intake as well as two rolls oriented perpendicular to one another, for example a horizontal and a vertical roll, can be provided on a roll stand having four driven rolls, per stand part, in particularly advantageous manner. This allows a compact and simple arrangement, particularly also with regard to the gear mechanisms between intake and rolls. In this connection, on a roll stand, the rolls can be connected to act with one another by way of two bevel gears that mesh with one another, preferably at a cone angle of 45°. Furthermore, the two bevel gears of a roll stand that mesh with one another can be disposed in a cassette. It is immediately evident that by means of these embodiments of a roll stand, the forces and moments that act in the roll stand can advantageously be distributed particularly uniformly, by means of the arrangement of the bevel gears and rolls, and can be absorbed by the roll stand. A particularly long useful lifetime and great operational reliability are thereby guaranteed in the case of a roll stand according to these embodiments.

Alternatively or cumulatively to the above characteristics, a roll stand having rolls for absorbing rolling forces that occur during rolling of elongated material is proposed, which roll stand is characterized by a stand body that has at least two metal stand sheets, whereby the metal stand sheets are disposed parallel to one another and perpendicular to the rolling forces. The provision of two metal stand sheets according to the proposed arrangement brings about a very stable embodiment of a roll stand, which furthermore can be produced with little material expenditure and consequently in very cost-advantageous manner.

In addition, bracket pieces can be provided on a roll stand, in accordance with the number of rolls, which pieces absorb the rolling forces and transfer them to the metal stand sheets. This embodiment of a roll stand also ensures operationally reliable and long use during rolling, in that the rolling forces that occur can be uniformly transferred to the roll stand.

In order to accomplish the task stated initially, alternatively or cumulatively to the above characteristics, a roll stand is proposed for absorbing rolling forces that occur during rolling of elongated material, which roll stand is characterized by a hydraulic overload safety device. These hydraulic overload safety devices, which can be provided in accordance with the number of rolls on a roll stand, make it possible, on the one hand, to put roll stand back into an operationally ready state in simple manner. This can take place after set-up of a rolling mill with a roll stand, or also after a shut-off due to an overload, in that pressure is simply built up accordingly.

If the hydraulic overload cylinders of at least one roll stand can communicate with one another, they can advantageously allow simultaneous triggering of all the existing overload cylinders, for example in the event of a malfunction.

Also, in order to accomplish the task stated initially, a method for replacing roll stands in a rolling mill is proposed, which is characterized in that at least one roll stand is moved along an inclined change track. In this way, as has already been explained above, simple control of the displacement path is made possible, in advantageous manner, particularly even if a coupling on the roll stand is supposed to be closed or opened in this connection. An existing coupling can close automatically in this case, due to the displacement along an inclined change track, and can also remain closed automatically.

In particular, it is advantageous if the roll stand is lowered into a rolling position along the inclined change track. It is immediately evident that lowering the roll stand along the inclined change track, into a rolling position, allows automatic stopping or positioning of the roll stand, because automatic displacement of the stand out of the change track is prevented under the effect of gravity, as was already explained in detail above.

Likewise, on the one hand alternatively or cumulatively to this, in order to accomplish the task stated initially, a method for replacing roll stands in a rolling mill is proposed, which method is characterized in that at least one roll stand is displaced from its rolling position toward one side, and a further roll stand is displaced from its rolling position toward another side. On the other hand, accordingly, a method for replacing roll stands in a rolling mill is proposed, which is characterized in that at least two roll stands are displaced from their rolling position to a common side and to change positions that are spaced apart from one another by at least one roll stand width. These method steps offer the advantage that free space remains to the side or next to the displaced roll stands, for further assembly or set-up work, or also for intermediate storage of roll stands. In particular, a free space can advantageously be made available between two roll stands, in which space a further roll stand can be temporarily stored, without thereby impeding the other roll stands for set-Up.

In this connection, it should be emphasized that the “roll stand width” of the roll stands is the longitudinal expanse of the roll stands along a rolling axis or the rolling direction. Thus, the roll stand width extends axially to a main expanse direction of the rolling mill.

Preferably, in the case of the latter alternative solution, two roll stands are displaced by a roll stand width, together with at least one further roll stand, before the further roll stand is then displaced into its rolling position. This displacement, exerted axially along the rolling mill, brings about positioning of the further roll stand, without the first two roll stands having to be removed. Thus, very fast replacement of the roll stands takes place, and only a minimal expenditure of time has to be applied for this, just like the set-up time, and also the entire space that is needed for this process can be reduced to a minimum.

Alternatively or cumulatively to the methods explained above, a method for replacing roll stands in a rolling mill is proposed, which is characterized in that at least one intake of a roll stand is connected with a drive on a roll stand, by way of an intake coupling, in that a drive-side coupling part remains fixed in place, and the roll stand, with the coupling part on the roll stand side, is displaced in such a manner that the intake coupling closes. The circumstance that particularly fast and operationally reliable coupling of the roll stand with its drive can be guaranteed is advantageous for this method, but also in order to accomplish the task stated initially, because the two coupling parts of the intake coupling actually only have to be set onto one another, without undertaking any setting or adjustment work, particularly if the roll stand, in each instance, is guided on a suitable track. It is immediately evident that not only are the set-up times minimized, but also the operational reliability of such a coupling is maximized, on the basis of the simple structure, as was already explained above.

In interplay with the solutions indicated above, in particular, it is possible to make available four-roll stands that make it possible to push the stands into the rolling mill frame at an offset of 45°, in such a manner that the intake couplings couple automatically, the drive system has a compact construction, and the roll stand replacement takes place on the smallest possible space.

It is understood that the characteristics of the dependent claims can also be accumulated, in order to be able to also implement the advantages in cumulative manner. Further advantages, goals, and properties of the present invention are explained using the following description of appended drawings. In the drawing, the figures show:

FIG. 1 a rolling mill in a perspective schematic view;

FIG. 2 a front view of the first roll stand of the rolling mill according to FIG. 1;

FIG. 3 schematically, a three-roll stand having an intake and three driven rolls;

FIG. 4 schematically, a four-roll stand having two intakes and two driven rolls;

FIG. 5 schematically, a four-roll stand having two intakes and four driven rolls;

FIG. 6 a detail view of the arrangement according to FIG. 5, partly in section;

FIG. 7 a perspective view of the arrangement according to

FIGS. 5 and 6, including roll stand;

FIG. 8 the arrangement according to FIGS. 5 to 7 in a similar representation as FIG. 5, with the overload cylinders shown; and

FIG. 9 a detail view of the overload cylinders.

In the exemplary embodiment according to FIGS. 1 and 2, each stand position 57 has its own regulatable drive motor 51 and a distributor gear mechanism 52 having two power take-offs, in each instance, is assigned to a roll stand situated on the stand position 57, in each instance, in a rolling position 61. In this connection, the drive motors 51 rest on a foundation 50 that also carries the stand positions 57. The roll stands 12 in turn comprise four rolls, in each instance, which form a caliber for rolling material to be rolled. All the roll stands 12 according to this embodiment have the same construction, aside from the caliber diameters, which narrow in this exemplary embodiment, in a rolling direction, from roll stand 12 to roll stand 12, and can change their caliber in a different form in other exemplary embodiments.

The roll stands 12 of the even-numbered stand positions 57 are disposed at an incline, with reference to the horizontal, in this exemplary embodiment, in the rolling mill frame, within the rolling line, by 22.5° relative to a rolling axis corresponding to the rolling direction 17. Accordingly, the roll stands 12 of the odd-numbered stand positions 57 are disposed offset with reference to the horizontal, in the rolling mill frame, within the rolling line, by −22.5° relative to a rolling axis that corresponds to the rolling direction 17. Accordingly, a roll stand 12 is offset about the rolling axis by 45°, in each instance, relative to the next adjacent roll stand 12.

The individual roll stands 12, in this exemplary embodiment, sit on a guided change shoe 53 having rollers, in each instance. This special change apparatus allows stand replacement within a few minutes, in the most confined space possible.

The roll stand replacement of the even-numbered stand positions 57 takes place, in the rolling direction 17, from the right side of the rolling line. The roll stand replacement of the odd-numbered stand positions takes place, in the rolling direction 17, from the left side of the rolling line. A change carriage 54 that can be displaced on tracks, which are not numbered, and are supported by the foundation, is situated on each side of the rolling mill, for accommodating not only the roll stands 12 that are in use until a replacement takes place, but also the roll stands 12 being prepared for use. Likewise, a roll stand extraction apparatus 55 having a hydraulic extraction cylinder is situated on each rolling mill side, for each roll stand 12, which apparatuses are also mounted on the foundation 50. Replacement of individual roll stands 12 is possible without problems, using these roll stand extraction apparatuses 55.

The roll stands 21 that are in use are pulled out of the rolling mill frames or out of their stand position 57, onto the change carriage 54, in each instance, for replacement, using the cylinder of the roll stand extraction apparatus 55, whereby they describe an arc on a change track 60 and, from a slanted position of 22.5° or −22.5°, in their change position 61 achieve their horizontal position on the change carriage 54, in a change position 58. Afterward, the change carriage 54 moves along the rolling direction 17 by a stand distance. Now, the roll stands 12 made available for insertion are situated in front of the rolling mill frame opening or, with their change position 59, in front of the stand position 57, and can be pushed onto the stand position 57, into the rolling position 61 within the rolling mill frame, using the cylinder of the roll stand extraction apparatus 55. When the roll stands reach a slanted position of 22.5° or −22.5°, respectively, as they move on the change track 60, and are brought into the rolling position 61, intake couplings 56 automatically couple, in order to transfer the drive power of the drive motors 51 to the roll stands 12.

The automatic coupling of the intake couplings is facilitated by means of the slanted position of the change track 60, of 22.5° or −22.5°, respectively, in the region of the rolling position 61, because no further forces are required for the coupling process, due to gravity. The roll stand extraction apparatus 55 accordingly needs only a fraction of drive power for moving the roll stands 12 into the rolling positions 57, as compared with the drive power for moving the roll stands 12 out after use. Also, the inclined change track 60 brings about great operational reliability during rolling, because the roll stands 12 lie against the stand position 57, in each instance, because of their own weight, and are positioned in this manner. In this regard, if applicable, as is particularly true in this exemplary embodiment, an additional securing device for positioning the roll stands 12 can be eliminated.

The roll stands 12 taken out of the rolling mill, which are now mounted on the change carriage 54, displaced accordingly, can be taken from the change carriage 54 after rolling operation has started again, using a crane, passed to further use, and replaced with new roll stands 12. Other measures, such as direct maintenance or the like, can also be undertaken there, if necessary. The change shoes 53 preferably remain on the change carriage 54 in this exemplary embodiment, when the roll stands 12 are taken off the change carriage 54. Because of the two change positions 58, 59 on the common change carriage 54, it becomes clear that the set-up time and therefore the shut-down time of the rolling mill are reduced to a minimum, because the actual transport of the roll stands 12 to the rolling mill and away from the rolling mill is uncoupled from the actual set-up.

As can be seen from FIG. 1, the alternating arrangement of the roll stands 12 along the rolling line or along the rolling direction 17 offers the further advantage that has already been mentioned, that the roll stands are disposed offset by 45° relative to the rolling axis, in each instance, as compared with one another. In this way, a burr that might be formed during rolling is smoothed again as it passes through the next roll stand 12, because abutting edges of the rolls 2, 3, 16 used in each roll stand 12 are in a different position, namely offset by 45°, at every passage through a roll stand 12.

In the sectional representation of the rolling mill according to FIG. 2, the arrangement of an even-numbered stand position 57 with an angle of 22.5° relative to the horizontal, and of the change apparatus disposed on the right side relative to the rolling direction 17 becomes clear. For the odd-numbered stand positions 57, the mirror-image arrangement applies, whereby a drive 51 of an even-numbered stand position 57 is disposed below the change position 58 of an odd-numbered stand position 57, in each instance. The alternating placement of the drives 51 furthermore allows the use of stronger drives, because now, more free space for an individual drive remains along the rolling direction 17, and drives having approximately twice the diameter as well as a consequently higher torque can be used. When using a roll stand 12 having only a single intake coupling, in such an embodiment, it is possible to do without a step-up or step-down, in other words a distributor gear mechanism, entirely, as long as the drive poser of a drive 51 configured to be stronger can be sufficient, even in the case of a non-stepped-up or non-stepped-down speed of rotation.

The alternating orientation of the change tracks 60, in each instance, furthermore directly produces the result, in this exemplary embodiment, that sufficient space for a further roll stand 12 remains in one of the change positions 39, between the roll stands 12 in the individual change positions 58, because at this level, the stand position 57 provided there is equipped or refitted from the other side. Therefore a corresponding set of new roll stands 12 can be made available by means of an offset of the change carriage 54 by one roll stand width.

The roll stands according to FIGS. 1 and 2 can be roll stands of the following type, for example:

-   -   three-roll stand having an intake 1 and three drive rolls 2, 3,     -   four-roll stand having two intakes 1 and two driven rolls 2, or     -   four-roll stand having two intakes 1 and four driven rolls 2, 3,         whereby if necessary, the angle of inclination of the change         track 60 can be adapted to the requirements, in each instance.

A three-roll stand having an intake 1 and three driven rolls 2, 3, as shown as an example in FIG. 3, has two pairs of bevel gears, for example, consisting of two bevel gears 7, 8, in each instance, which are provided on both sides of a driven roll 2 disposed coaxial to the intake, and which in turn drive a driven roll 3, in each instance. In this connection, the rolls 2, 3 are inclined at an angle of 120° relative to one another, and disposed in the roll frame 12. Such a unit can be used, in particular, not only in stretch-reduction rolling mills but also in dimensional rolling mills or in extraction rolling mills. In this connection, such roll stands 12 can be configured with or without a quick-release axle 4, and can be configured to be fixed or adjustable in inclination.

In the case of a three-roll stand, an optimal angle of the change track 60 occurs, as is immediately evident, in the inclined section of 30° and −30°, respectively, relative to the horizontal, because an angle distance of 60° occurs in each instance between an axis of symmetry of a roll 2, 3 and its outer edges, which abut one another. With such an offset, as was already explained above in connection with a four-roll stand, a burr that occurs in a first roll stand 12 can be smoothed again in the following roll stand 12.

It is immediately evident that for two roll stands 12 disposed in the rolling direction 17, any other angle offset is also possible, but in the explained arrangements, with 45° or 60° offset, the rolling forces that act on a burr reach a maximum, and thus the best possible rolling result is achieved. If necessary, however, a roll surface that deviates from the circular shape can also be provided, insofar as a smaller radius is present at the abutting edges of two rolls 2, 3—in the plane of the drawing in FIGS. 3 to 6—than in the region of the axis of symmetry of a roll, and as a result, a constant rolling force can be achieved at the circumference of the rolled material. Likewise, in the case of special rolling procedures, different arrangements of the rolls in the roll stand 12 and/or an offset of the roll stands 12 or of the rolls 2, 3 that deviates from 45° or 60°, or different or also changeable angles of inclination can be provided.

The quick-release axle 4 in a roll stand 12 according to FIG. 3 supplies the driven roll 2 as well as the rolls 3 also driven by means of the bevel gears 7, 8 with the drive poser supplied by way of the intake 1. The roll stand 12 has a coupling part 11 on the roll stand side, of the intake coupling, which stands in a rotationally active connection with the quick-release axle 4, and which in turn, as was explained in the above exemplary embodiment, interacts with a drive-side coupling part of the intake coupling, whereby the roll stand 12 automatically brings about coupling-in of the two coupling parts by means of the inclined change track 60.

In this connection, the two coupling parts are always oriented coaxial to one another, in the region of the rolling position 61, as they are also in the further explained embodiments. Thus, the axis of rotation 15 of the intake coupling coincides not only with the axis of rotation of the two coupling parts but also with an axis of rotation of the driven roll 2. Furthermore, the axis of rotation 15 of the intake coupling runs parallel to the change track 60.

If necessary, the non-driven rolls 3 can also be configured as drag rolls.

In the case of a four-roll stand according to FIG. 4, with two intakes 1 and with two driven rolls 2, these are disposed to lie opposite one another and connected with one of the two intakes 1, in each instance. A total of two drag rolls 16 are provided, offset by 90°, in each instance, relative to the two driven rolls 2. This arrangement, too, is preferably held in a roll stand 12, not shown here, and can be used not only for stretch-reduction rolling mills but also for dimensional rolling mills or for extraction rolling mills. In this connection, such roll stands 12 can also be configured with or without a quick-release axle 4, as well as in fixed manner or so as to be adjustable in inclination.

In the case of a four-roll stand having two intakes, in contrast to the three-roll stand explained above, the two drag rolls 16 are uncoupled from the driven rolls 2. A rotation of these drag rolls 16 therefore takes place only by way of the movement of the rolled material along the rolling direction 17, whereby the drag rolls 16 are dragged by way of a contact pressure that acts on the rolled material.

In contrast to the above exemplary embodiment, the driven rolls 2 of the four-roll stand do not have coaxial axes of rotation to the quick-release axles 4 and to the intakes 1. An eccentric bushing is provided, in each instance, between the quick-release axle 4 and the driven roll 2, as well as on the side of the driven roll 2 that faces away from the quick-release axle. This eccentric bushing 9 allows inclined contact of the roll, in each instance, with the rolling material to be rolled, whereby the drag rolls 16 also have related eccentric bushings 9. The contact pressure and the rolling dimension can be adjusted in accordance with the requirements, by way of a force exerted on the eccentric bushing 9. In this embodiment, an overload cylinder that is not shown in FIG. 4 acts on the eccentric bushing 9, to produce the contact pressure.

The two intakes 1 of a four-roll stand shown in FIGS. 5 to 8, having four driven rolls 2, 3, but also the four-roll stand explained above, having two driven rolls 2, have axes of rotation 15 of their intake couplings that are oriented parallel to one another. This arrangement guarantees automatic closing of the intake coupling during set-up and lowering of the roll stand 21 onto the change track 60, into the rolling position 61.

The four-roll stand shown in FIGS. 5 to 8, having two intakes 1 and four driven rolls 2, 3, in deviation from the three-roll stand according to FIG. 3, has two roll units, in order to absorb great stand torques and rolling forces. Two rolls 2, 3 that stand perpendicular to one another are driven, in each instance, by way of two bevel gears 7, 8 that mesh with one another, by way of an intake 1, in each instance, whereby the bevel gear angle amounts to 45°.

In this connection, the bevel gears 7, 8 that lie on the inside, in each instance, are mounted separately in a cassette 6 that is guided in the roll stand in displaceable manner. Furthermore, the bevel gears 7, 8 sit at the end of short shaft pieces of a related quick-release axle 4, 5, in each instance, so that they can be displaced with a multi-wedge profile; the other end of the axle sits on the roll shafts with an inner multi-wedge profile. The shaft pieces are mounted in the eccentric bushings 9 by means of roller bearings. In the case of an eccentric displacement of the rolls 2, 3, the cassettes 6 are also displaced, and thus the bevel gears 7, 8 that are firmly mounted in them are also displaced, and thereby shift in the multi-wedge profile of the roll ends. The eccentric bushings 9 are provided with a flattened region, on both sides, on the side that faces away from the rolled material. The center of the eccentric device is shifted in the roll stand, in the rolling direction 17. The inclination of the rolls 2, 3 or the rotation of the eccentric devices takes place by way of threaded pins in the roll housing, which press on one side of the flattened region. Brackets with threaded pins enclose the flattened region of the eccentric bushing 9. Spur gears that mesh with a hollow gear sit on the threaded pins. The threaded pins are rotated with the spur gears set on them, in the same path and at the same time, by means of rotating the hollow gear in the circumference direction, thereby changing the radial position of the rolls. The roll shaft units, configured as quick-release axles 4, 5, are braced with a threaded rod 10 and a clamp nut 10.

The roll stand 12, in the exemplary embodiment according to FIGS. 5 to 8, has two metal stand sheets 13 that enclose four bracket pieces 14. In this regard, the metal stand sheets 13 absorb the rolling forces. The bracket pieces 14 are machined before they are connected, preferably welded, and lie firmly in the metal stand sheet 13 that encloses them, with their shoulders, in this exemplary embodiment. It is understood that in place of such a stand construction, a conventional roll stand, for example as a cast body, can also be used.

The cassettes 6, in particular, form separate stand parts, in this connection, so that in the present case, two separate stand parts are provided, which have an intake 1, in each instance, which is connected, in each instance, with two rolls 2, 3 oriented perpendicular to one another. The cassettes 6 or the separate stand part in turn are mounted, once again, on the stand body formed by the metal stand sheets 13. In other embodiments, it is possible that two rolls that lie opposite one another, in each instance, are provided in a stand part. Great stand moments and rolling forces can be absorbed by means of the separate stand parts.

Conventional shear pins or other known devices can be used as overload protection. In the present exemplary embodiment, as is particularly shown in FIG. 8, hydraulic overload cylinders 20 are provided, thereby making it possible to implement an overload security device that can rapidly be put back into its operational state, which can be done in simple manner, for example by means of making the corresponding pressure available. Also, a corresponding signal can be picked up quickly and in operationally reliable manner, and can be used for further reactions, such as shut-off of the entire rolling mill, for example.

The hydraulic overload cylinders 20 consist, as is particularly shown in detail in FIG. 9, of cylinder bodies 26, cylinder lids 21, and pistons 25. In a roll stand 12, one of the rolls 2, 3, in each instance, has two overload cylinders 20, which act on the eccentric bushings 9. A roll stand 12 of a four-roll stand accordingly has eight separate overload cylinders 20.

A holding pin 23 having a twist prevention device 22 passes through the cylinder lid 21. In this way, fine-tuning of a gap between a guide piece 27 of the overload cylinder 20 and the eccentric bushing 9 that lies below it takes place. Oil or grease that is under high pressure is applied to a cylinder capacity 24 formed between the piston 25 and the cylinder lid 21, in this exemplary embodiment, whereby other media can also be used accordingly, if necessary. The overload cylinders 20 are connected with one another by means of pipelines, by way of pressure connectors 28, in this exemplary embodiment, but this can also be eliminated, if necessary. However, common triggering of the overload security devices for all the rolls 2, 3 at the same time cannot be ensured so easily, in the absence of communication by means of the pressure connector 28 or other means for signal transmission. The overload cylinders 20 are adjusted, by means of a common valve, in such a manner that they open at a set parting force, and the guide piece 27 releases the eccentric bushings 9 with the inner parts. This takes place, in contrast to the conventional shear pins, in which the pins do not necessarily all break at the same time, either at the same time or in particular, also in reversible manner.

Such an overload security device, particularly also a synchronization with regard to all the rolls of a roll stand, is particularly advantageous for extraction rolling mills.

REFERENCE SYMBOLS

-   1 intake -   2 driven roll -   3 driven roll -   4 quick-release axle -   5 quick-release axle -   6 cassette for bevel gear pair -   7 bevel gear -   8 bevel gear -   9 eccentric bushing -   10 threaded rod with clamp nut -   11 coupling part of the intake coupling, on the roll stand side -   12 roll stand -   13 metal stand sheet -   14 bracket piece -   15 axis of rotation of the intake coupling -   16 drag roll -   17 rolling direction -   20 overload cylinder -   21 cylinder lid -   22 twist prevention device -   23 holding pins -   24 cylinder capacity -   25 piston -   26 cylinder body -   27 guide piece -   28 pressure connector -   50 foundation -   51 drive motor -   52 distributor gear mechanism -   53 change shoe -   54 change carriage -   55 roll stand extraction apparatus -   56 intake coupling -   57 stand position -   58 change position -   59 further change position -   60 change track -   61 rolling position 

1. Rolling mill for rolling elongated material, having multiple roll stands (12) disposed in a line, forming a central caliber opening, wherein the roll stands (12) are disposed in a stand position (57), in each instance, and can be displaced into at least one change position (58, 59), in each instance, wherein each stand position (57) has an intake coupling, and the intake coupling has a coupling part (11) on the roll stand side, as well as a coupling part on the drive side, wherein the drive-side coupling part is provided in axially fixed manner on the stand position (57).
 2. Rolling mill according to claim 1, further comprising two intake couplings per roll stand (12) and per stand position (57), wherein the two intake couplings are in effect axial to their axes of rotation (15), in each instance, and the axes of rotation (15) are oriented parallel, and wherein the two intake couplings are disposed on one side of the line.
 3. Rolling mill according to claim 1, wherein a drive having a drive motor (51) is provided on at least one stand position (57), which motor is connected with a distributor gear mechanism (52), which has at least two power take-offs, wherein the power take-offs, in each instance, have a drive-side coupling part of an intake coupling.
 4. Rolling mill for rolling elongated material, having multiple roll stands (12) disposed in a line, forming a central caliber opening, wherein the roll stands (12) are disposed in a stand position (57), in each instance, and can be displaced into at least one change position (58, 59), in each instance, wherein the change position (58) is provided on a change carriage (54), wherein the change carriage (54) has at least one further change position (59).
 5. Rolling mill according to claim 4, wherein the change carriage (54) has at least four change positions (58, 59), one change position (58) and one further change position (59), in each instance, for two stand positions (57), in each instance, wherein the two change positions (58) are spaced apart from one another in accordance with the distance between the two stand positions (57), and the two further change positions (59) are spaced apart from one another in accordance with the distance between the two stand positions (57).
 6. Rolling mill according to claim 5, wherein the change positions (58) and the further change positions (59) are spaced apart from one another, in each instance, by the width of a roll stand (12), preferably by the distance between the stand positions (57).
 7. Rolling mill according to claim 1, further comprising at least one roll stand extraction apparatus (55) having a hydraulic extraction cylinder.
 8. Rolling mill having at least two driven rolls (2, 3) and having at least two intakes (1), wherein each intake (1) has a coupling part (11) on the roll stand side, and the coupling parts (11) on the roll stand side are oriented in parallel and in the same direction.
 9. Rolling mill having at least four driven rolls (2, 3), wherein two rolls (2, 3), in each instance, are mounted on a common stand part, wherein the two stand parts in turn are mounted on a stand body.
 10. Rolling mill according to claim 9, wherein an intake (1) as well as two rolls (2, 3) oriented perpendicular to one another are provided per stand part.
 11. Rolling mill according to claim 10, wherein the rolls (2, 3) are connected to act with one another by way of two bevel gears (7, 8) that mesh with one another, preferably having a cone angle of 45°.
 12. Rolling mill according to claim 11, wherein the two bevel gears (7, 8) that mesh with one another are disposed in a cassette (6).
 13. Rolling mill having rolls for absorbing rolling forces that occur during rolling of elongated material, comprising a stand body that has at least two metal stand sheets (13), wherein the metal stand sheets (13) are disposed parallel to one another and perpendicular to the rolling forces.
 14. Rolling mill according to claim 13, wherein bracket pieces (14) are provided, corresponding to the number of rolls (2, 3), which pieces absorb the rolling forces and transfer them to the metal stand sheets (13).
 15. Rolling mill for absorbing rolling forces that occur during rolling of elongated material, comprising a hydraulic overload security device.
 16. Rolling mill according to claim 15, wherein overload cylinders (20) that communicate with one another are provided in accordance with the number of rolls (2, 3).
 17. Method for replacing roll stands (12) in a rolling mill, wherein at least two roll stands (12) are displaced from their rolling position (61) to a common side and to change positions (58, 59) that are spaced apart from one another by at least one roll stand width, wherein the two roll stands (12) are displaced by a roll stand width, together with at least one further roll stand (12), before the further roll stand (12) is then displaced into its rolling position (61).
 18. Method for replacing roll stands (12) in a rolling mill, wherein at least one intake (1) of a roll stand (12) is connected with a drive on a stand position (57), by way of an intake coupling, in that a drive-side coupling part remains fixed in place, and the roll stand (12), with the coupling part (11) on the roll stand, is displaced in such a manner that the intake coupling closes. 